This invention relates generally to an improved valve for use in oil and gas wells or the like. More specifically, but not by way of limitation, this invention relates to a flow control valve including a valve member that is caused to move between open and closed positions by rotation of the tubing.
In operation performed in oil and gas wells or the like, it is desirable to be able to provide as large a flow path through a tool situated in the well as possible while still maintaining the functional integrity of the tool. Valves, particularly ball valves, provide a relatively large flow path through the housing in which they are contained. Further, it is desirable to be able to provide, when the valve is closed, a fluid tight seal preventing flow through the tool. Again, ball valves are particularly adapted to such situations since the sealing structure is annular in configuration and is relatively simple to construct.
A relatively large number of U.S. patents have issued providing various apparatus for utilizing valves of the ball valve type in tools lowered into oil and gas wells. One such patent is U.S. Pat. No. 4,508,173 that illustrates a flow control valve of the ball type for use in oil and gas wells that is actuated by rotation of the tubing and that will hold pressure therethrough regardless of whether the pressure differential exists across the valve from above to below or from below to above. The ball valve illustrated in this patent is actuated by a force couple that is generated by a pair of reciprocating actuating members which are caused to move in opposite directions during the pivoting of the ball valve from one position to the other. While such structure operates very effectively, such a valve is relatively expensive and complex to construct.
It is therefore one object of this invention to provide an improved flow control valve of the ball type that is arranged to be lowered into a well bore and that is moved between open and closed positions by rotation of the well tubing through a simplified actuating mechanism that is relatively simple and inexpensive to manufacture.